Scientific Highlights

A team with three researchers from the ETH Domain has been awarded a prestigious EU grant. Today, they received the contract signed by the EU confirming the extraordinary 14 million euros funding. With it, they will investigate quantum effects which could become the backbone of future electronics.

It is difficult for X-rays to compete in spatial resolution with electrons, but they can probe relatively large bulk sample volumes at atmospheric pressure in a non-destructive manner. This makes X-ray tomography a promising tool to investigate catalytic nanoporous materials under real operating conditions. In this work researchers from Karlsruhe Institute of Technology and the University of Bremen in Germany compared X-ray ptychographic tomography, electron tomography and focused ion beam-scanning electron microscopy performed on a nanoporous sponge-like gold material with numerous applications, including selective oxidation and sustainable production of chemicals. As it turns out, the X-ray based method is the most suitable for in situ or sequential post-mortem analysis of volumes after thermal annealing, which researchers want to pursue in the future.

The reliable electrical detection of magnetic skyrmions is of fundamental importance for the application of such topological magnetic quasi-particles for data storage devices. Researchers in a joint collaboration between the University of Leeds and the PolLux endstation have investigated the electrical detection of isolated magnetic skyrmions in applications-relevant nanostructured devices, observing the presence of a strong skyrmion-dependent contribution to the Hall resistivity.

Our experiments, published in the September issue of Structural Dynamics, demonstrate the feasibility of time-resolved pump-multiprobe X-ray diffraction experiments on protein crystals using a split-and-delay setup which was temporarily installed at the LCLS X-ray Free Electron Laser.

Our image of a diamond structure was published on the cover page of the September 2018 issue of the journal "Materials Today". The corresponding paper reports on the nano-frabrication of micro-optical elements in diamond.

The electronics industry expects a novel high-performance transistor made of gallium nitride to offer considerable advantages over present-day high-frequency transistors. Yet many fundamental properties of the material remain unknown. Now, for the first time, researchers at the Paul Scherrer Institute PSI have observed electrons while they were flowing in this promising transistor. For that they used one of the world's best sources of soft X-rays at PSI's Swiss Light Source SLS.

Data storage devices based on novel materials are expected to make it possible to record information in a smaller space, at higher speed, and with greater energy efficiency than ever before. Movies shot with the X-ray laser show what happens inside potential new storage media, as well as how the processes by which the material switches between two states can be optimised.

In March 2018, the nine-week MOOC “Introduction to synchrotrons and x-ray free-electron lasers” (abbreviated to “SYNCHROTRONx”) came online via the edX provider of the École Polytechnique Fédérale de Lausanne (EPFL), created by Phil Willmott of the Swiss Light Source, Paul Scherrer Institute. “MOOC” is an acronym for “massive open online course”, a teaching platform started in the first decade of this century, which has become increasingly popular in the last five to six years. MOOCs have no limits to participation and are free. Some of the most popular MOOCs can attract many tens of thousands of participants. Even the most specialized subjects may have an initial enrollment of over a thousand, more than an order of magnitude larger than that typically found in traditional higher education. There were over 70 million MOOC enrollments covering nearly 10’000 subjects offered by the top five providers in 2017 alone!

The writing and deletion of magnetic Skyrmions is a fundamental step towards the fabrication of memory devices based on this promising spin configuration. Researchers at the Korea Institute of Technology have demonstrated the writing and deleting of isolated magnetic Skyrmions at room temperature in ferrimagnetic multilayer superlattice stacks using electrical currents.

Dr. Caterina Biscari, Director of the ALBA Synchrotron in Spain and Vice Chair of LEAPS, League of European Accelerator-based Photon Sources, presented the LEAPS Strategy 2030 to Jean-David Malo, Director, Directorate General Research and Innovation, European Commission

“A world where European science is a catalyst for solving global challenges, a key driver for competitiveness and a compelling force for closer integration and peace through scientific collaboration.” This is the vision of LEAPS, League of European Accelerator-based Photon Sources, on which the LEAPS Strategy 2030 is based. Director Jean-David Malo, DG Research and Innovation, received the strategy today at the Bulgarian Presidency Flagship Conference on Research Infrastructures.

In the week of March 18-23 PSI welcomes 20 PhD students and postdocs taking part in
the HERCULES 2018 school on Neutron and Synchrotron Radiation. They will attend
lectures and perform two days of practical courses at several beam lines of the Swiss
Light Source.

Classical theory predicts that supersaturated carbonate solutions consist mostly of ions and ion pairs, with a small number of larger clusters present in the solution. The population of the different sized clusters in a solution is solely defined by the cluster’s size dependent Free Energy. If clusters are large enough they serve as nucleation germs for a new solid phase. The nucleation occurs once the surface free energy barrier posed by the new solid-liquid interface is overcome by the free energy win from bulk phase growth. However, for calcium carbonate solutions, this classical view has been challenged by the emergence of non-classical theories. In a novel experiment, using synchroton X-ray absorption spectroscopy, the molecular structure around the solvated calcium ion in dilute supersaturated calcium carbonate solutions was probed in situ. The results obtained definitively show that supersaturated calcium carbonate solutions are dominated by ions and ion pairs. The presence of larger oligomers as predicted by non-classical theories was not detected. Moreover, predictions from independent theoretical calculations on the structure of supersaturated calcium carbonate solutions were in congruence with the experimental results. As a consequence, it is quite clear that the nucleation of calcium carbonate follows a classical pathway.

Using a unique set of well-defined silica-supported Ni nanoclusters (1–7 nm) and advanced characterization methods it was proved how structure sensitivity influences the mechanism of catalytic CO2 reduction, the nature of which has been long debated.